Determination of Water Content in 1-Iodine octane, Octyl iodide Using Karl Fischer Titration

Product Group

Halogenated hydrocarbons

General Information concerning the product group

Halogenated hydrocarbons

Halogenated hydrocarbons can in most cases be titrated by the Karl Fischer method without any problems as is the case for hydrocarbons. No interferences are to be expected from the chemical structure. To overcome solubility problems of unpolar or weakly polar substances, the addition of a solubiliser to the solvent is necessary. In the case of long-chain and cyclic hydrocarbons, long-chain alcohols (e.g. decyl alcohol) or chloroform are thus recommended. Toluene, xylene or chloroform improve the solubility of aromatic compounds. Recommended methods are both the volumetric titration with one or two component reagents, as well as the coulometric analysis. The latter is predominantly applied for low water concentrations (< 0.1 %). If chlorinated hydrocarbons contain free chlorine it is necessary to reduce it prior to KF analysis. This is best achieved through attachment to unsaturated compounds, e.g. through conversion with tetradecene.

Special Information concerning the sample and the methods

Water determination for this substance can be carried out following standard methods.

Procedure: The titration medium is first placed into the titration cell and titrated dry by means of the titrant. Then the sample is added with a syringe (exact sample weight determination through weighing of syringe before and after injection) or volumetric pipette and the titration is started.

Procedure: The titration medium is first placed into the titration cell and titrated dry by means of the titrant. Then the sample is added with a syringe (exact sample weight determination by weighing of syringe before and after injection) or volumetric pipette and the titration is started.

Procedure: The Karl-Fischer reagent is placed into the cathode and anode compartment of the titration cell with diaphragm. The coulometer is started and the solvent is titrated dry. After pretitration and stabilisation of drift the sample is injected into the titration cell with a syringe (exact sample weight determination by weighing of syringe before and after injection) and the water determination is started.

Procedure: The Karl-Fischer reagent is placed into the titration cell without diaphragm. The coulometer is started and the solvent is titrated dry. After pretitration and stabilisation of drift the sample is injected into the titration cell with a syringe (exact sample weight determination by weighing of syringe before and after injection) and the water determination is started.